Looper carrier for sewing machine



April 1960 B. N. PIERCE 2,931,328

LOOPER CARRIER FOR SEWING MACHINE Original Filed Nov. 21, 1951 4 Sheets$heet 1 [nve ntor. BernardNPiGrce His Attorneys April 5, 1960 B. N. PIERCE LOOPER CARRIER FOR SEWING MACHINE Original Filed Nov. 21, 1951 4 Sheets-Sheet 2 fnv en tor Bern ard Mfa'erce His A6150 rneys April 1960 B. N. PIERCE 2,931,328

LOOPER CARRIER FOR SEWING MACHINE Original Filed Nov. 21, 1951 4 Sheets-Sheet 3 s O S; 3 0 Jr 3 O R Inventor: Bern arcZMPa'erce y M4 M April 5, 1960 B. N. PIERCE 2,931,328

LOOPER CARRIER F OR SEWING MACHINE Original Filed NOV. 21, 1951 4 Sheets-Sheet 4 HisAtf/orne ys Inventor Bernard MPerce nited States PatentO a LOOPER CARRIER FOR SEWING MACHINE Bernard N. Pierce, West Hartford, Conn., assignor to The Merrow Machine Company, Hartford, Conn., a corporation of Connecticut Original application November 21, 1951, Serial No. 257,620, new Patent No. 2,879,733, dated January 16, 1959. Divided and this application August 18, 1958, Serial No. 755,552

Claims. (Cl. 112 -162) 2,931,328 Patented Apr.. 5, 196Q 22 forrotation therewith. A lower cam cylinder 28 is fixedly secured to lower shaft 24 for rotation with shaft 24. At the right hand end of the machine, shaft 24 is extended through the right hand end wall and a hand wheel and pulley assembly 30 is mounted upon the projecting end of shaft 24 whereby shaft 24 may be driven in rotation from a suitable source of power. As best seen in Fig. 2, carn cylinder 28 is formed with gear teeth 32 which mesh with a set of gear teeth 34 on upper cam cylinder 26 whereby rotary movement of lower cam cylinder 28 by rotation of shaft 24 is transmitted to upper ture for accurately guiding and maintaining alignment of a looper carrier during the highly irregular movement required of such carriers. I

In the achievement of the foregoing and other objects, a block having an elongated central opening therein is mounted upon the machine frame with a stationary rod extending across the opening and slidably supporting a sleeve. Projecting from the sleeve is a stud upon which a looper carrier is journaled for rotation. This looper carrier includes a pair of arms, each arm having a cam follower roller mounted on its distal end respectively engaging cam grooves in upper and lower cam cylinders. Correlated rotation of the cam cylinders drives the looper carrier in a motion which pivots the carrier about the axis defined by the stud and at the same time reciprocates the stud relative to the frame.

Other objects and features of the invention will become apparent by reference to the following specification taken in conjunction with the accompanying drawings.

In the drawings:

Fig. 1 is a front side elevation of a sewing machine embodying the invention;

Fig. 2 is a front side elevation of the machine of Fig. 1 with certain partsremoved and .othersshown partially in section; H J I.

Fig. 3 is a left end view of the machine frame;

Fig. 4 is a transverse cross sectional view of the machine of Fig. 1 taken on a vertical plane passing approximately through the center of the frame cap;

Fig. 5 is a view showing the inner side of the frame cap with certain parts removed and others shown partially in section;

Fig. 6 is a view of the inner side of the frame cap, similar to Fig. 5, but showing additional parts in place on the cap;

Fig. 7 is a detail view of certain parts shown in Fig. 6;

Fig. 8 is a detail cross sectional view taken on a vertical plane passing through the pivot of the lower looper carrier.

Referring first to Figs. 1 through 3, a sewing machine embodying the present invention includes a main frame casting 10 which is formed with a mechanism compartment 12, one side of which is closed by a frame cap 14 removably secured to frame 10 as by screws 16. As best seen in Fig. 3, the end wall of main frame 10 is formed with an aperture 18 through which the operative parts of a looper mechanism to be described below project from mechanism compartment 12 into operative relationship with a needle assembly 20.

Upper and lower shafts 22 and 24 respectively are journaled for rotation within frame 10. Upper shaft 22 carries an upper cam cylinder 26 which is fixed to shaft cam cylinder 26 and hence to upper shaft 22.

Upper cam cylinder 26 is formed with a cam groove 36 which is constructed to receive a cam follower in the form of a roller 38 rotatably supported upon the upper end of an upper looper carrier designated generally 40. A cam groove 42 cut into lower cam cylinder 28 is constructed to receive a similar roller 44 mounted upon the lower end of upper looper carrier 40. Cam cylinder 28 is provided with a second cam groove 46 which receives a cam follower roller 48 mounted upon a lower loopercarrier designated generally 50. I a

Upper looper carrier 40 includes a pair of oppositelproiecting arms 52 and 54 which are joined at their innerends by a hub 56. An upper looper needle 58 is mounted in a third arm 60 which projects from hub 56 and is provided with a central bore, not shown, within which the shank of needle 58 is clamped as by set screw 62.

Upperlooper carrier 40 is supported upon the interior surface of frame cap 14 for an irregular motion dictated by a configuration of cam grooves 36 and 42 which re. quires that carrier 40 be able to pivot about the axis of hub 56 and also be movable in a manner which oscillates hub 56 in a horizontal path extending from left to right in Figs. 1 and 2. Details of the structure which supports upper looper carrier 40 on frame cap 14 are best shown in Figs. 4 through 6.

Carrier 40 is supported from a block 64 which is fixedly mounted upon the inner surface of frame cap 14 as by screws 66. As best seen in Fig. 5, block 44 is constructed with an elongated central opening 68. A stationary rod 70 extends across aperture 68 and is fixedly secured to block 64 as by set screws 72. A sleeve 74 is slideably mounted upon rod 70 and provided with a projecting stud 76 which'is receivedwithin a central bore inhub 56 of cafiier 40 'wh'erebycarrier 40 is supported for pivotal movement on stud 76. As best seen in Fig. 6, sleeve 74 may slide along rod 70 while at the same time carrier 40 may pivot about stud 76 which moves with sleeve 74.

To guide and maintain accurate alignment of looper carrier 40 during movement, block 64 is constructed with upper and lower rails 78 and 80 respectively which slideably engage the respective upper and lower arms of looper carrier 40. A guide bar 82 is mounted upon the inner surface of block 64 to overlie stud 76 and hub 56 to slideably engage the opposite side of looper carrier 40 to assist rails 78 and 80 in maintaining the carrier in a generally vertical plane. Guide bar 82 is secured to block 64 as by screws 84 and 86 (Figs. 1 and 6). Screw 86 passes through frame cap 14 and block 64 and is threaded into guide bar 82. Screw 84 passes through a foot 82' on the guide bar and is threaded into block 64.

Frame cap 14 is formed with an aperture 88 through which a thread take up member 90 mounted on sleeve 74 may project.

As best seen in Figs. 6 and 8, lower looper carrier 56 includes a hub 92 having a tapered central bore 94 which is rotatably supported upon a complementary tapered stud 96 which is locked to frame cap 14 by a nut 98. Lower looper needle 100 is mounted in an arm 102 fixed to the body of carrier 50 in a fashion similar to that in which upper needle 58 is supported on upper carrier 40.

K th" ad'tatien'p 104 isrnou'nted on the body of lower carrier 50" as by a screw 106 and projects through an opening 108 in frame cap 14.

The configuration of cam grooves 36, 42 and 46 is selected tobe such that the upper and lower needles mov in ofierative relationship With needle assembly 20 fsifiee V respective bearing surfaces on said block.

needle assembly 20 is driven from-upper shaft 22, to a which upper cam cylinder 26; is fixed, movement of the variousneedles is interrelated, in a manner well-known in tlie art, by the orientation of the cam cylinders on theirrespective'shafts. V v 7 While: I have described but one embodiment of my invention, it willflbe apparent to those skilled in the art that the disclosedembodiment may be modified. There fore, the foregoing specification is to be considered eit emplary rather than limiting and'the true scope of my invention is that defined in the following claims;

l Asewingmachine comprising a frame, a frame cap closing an openingin said frame, cylindrical cams rotatably supported-in said frame, a rod mounted on said frame cap parallel to the axes of said cams, a, sleeve slide able'on said rod, a looper carrier mounted on said sleeve for pivotal movement about an axis perpendicular to said rod-,aguide' barspaced from said framecap opposite said rod having a bearing surface for engaging the side of said carrier opposite said sleeve, arms on said carrier extend; mg in opposite directions from the pivotal axis of said carrier 'withfo'llowers' for engagementwith s'aid' cams', and coplanar rails'on opposite sides of saidaxis having bearing surfaces forslidably engaging the sides, of saidarms adjacents'aid sleeve. 7 r I p 21 In a sewing machine, a looper carrief' assembly comprising" a block, a rod mounted in said block, bearing surfaces on said block on opposite sides of said fed, a sleeve slideable on said rod, a looper carrier pivotally mounted on saidslee've, arms on said carrier extending oppositely from the pivot for engaging said bearingsur' faces,- and a guide bar mounted on said block and spaced from said rod, said guide bar having a bearing surface for engaging said looper carrier opposite s'aid rod;

3.- In a sewing machine, ajlooper' carrier assembly com; prising a block, an elongate rod mounted upon said block, a sleeve slideably mounted upon said rod', a looper carrier mounted upon said sleeve for pivotal" movement on said sleeve about an axis normal to tl 1e anis of said rod, a pair of oppositelyjprojec'ting arms on said carrier having side surfaces lying in i Pla e normal to theaiiis of pivo'taimovement of said carrier, a pair of coplanar 4. In a sewing machine, a looper carrier assembly comprising a block having an elongate central opening therein, a rod mounted in said block and extending longitudinally across said opening, a sleeve slide ably mounted s'liding'bearing engagement with the respective bearing surfaces on said block. s v

, 5. In a sewing machine, a looper carrier assemblycom' prising a block having an elongate central opening ther in, a rod mounted within said block and extending longi tudinally across said opening, a sleeve slideably mounted upon said fed, a stud projecting from said ,sle'ev'ein a direction normal to the axis of said rod outwardlylbeyond one side of said block, a looper carrier having a hub pivotally supported upon said stud, a pair of arms on said carrier projectingin opposite directions from said hub and having side surfaces lying in a plane normal to theaxisfof pivotal movement of said carrie'r' upon said stud, a pair." of coplanarfbearingsurfac'es' oii said blocklying in ajplane paralleltothej of saidrod, said hear: ing' surface being felongat'edin the direction parallel to. theiaxis of said rod and being of relatively narrowaansverse extent and being spaced from said rod to enga e the respective side surfacesof said arms of saidearrier't adjacent the distal ends of'said arms, anda guide bar. mounted upon said block and spaced from-said rod, said guide bar having a bear'ingsurface slideably' engaging said hub of said carrier to maintain. said side surfaces of said arms in sliding engagement with said bearing surfaces on said block. 

